Lately, well... ever since I removed my air-pump on my '93 rx7 I've been having some electrical problems. Mainly my problems occur at start-up and shut-down. The car will not always turn over on the first try (especially after really short trips)and it will usually never turn over on the first try if I leave my radio on when the car turns off (b/c it will be on when the car turns back on). I thought that the battery was bad at first (Optima 51R) but I had it replaced with a brand new one and the problems persisted. I then thought it was a bad alternator but the thing pulls over 12volts while running (I think it was about 13.2). Just this morning when I got back I looked at my alternator and noticed that there was dust from the belt being worn down on the ridges around the pulley of the alternator. My thinking is that the belt is either too tight or too loose and thus causing my problems. Would it be wise to switch back to a 5 ribbed belt (stock) instead of a 4 ribbed belt (that I'm using now)? I used a 4 ribbed because it was the only one they had in the right length and we both figured it would do fine. Thanks in advance.

-Taylor